纳米硅氧多层薄膜低温调控及其发光特性  

Low temperature deposition and photoluminescence properties of silicon oxide multilayer films

作　　者：李云[1] 张博惠 高东泽 丛日东[1] 于威[1] 路万兵[1] LI Yun;ZHANG Bo-hui;GAO Dong-ze;CONG Ri-dong;YU Wei;LU Wan-bing(College of Physics Science and Technology,Hebei University,Bao Ding 071000,China)

机构地区：[1]河北大学物理科学与技术学院,河北保定071000

出　　处：《光学精密工程》2018年第8期1960-1966,共7页Optics and Precision Engineering

基　　金：国家自然科学基金青年基金资助项目(No.61504036);河北省自然科学基金青年基金资助项目(No.A2016201087);河北省高等学校科学研究指导项目资助项目(No.Z2015121)

摘　　要：为了研究硅量子点薄膜在太阳电池中的应用,本文采用甚高频等离子体增强化学气相沉积技术,低温制备了镶嵌有纳米晶硅(nc-Si)的纳米硅氧多层(nc-SiOx/a-SiOx)薄膜样品。TEM图显示,通过调整nc-SiOx层的厚度,实现了薄膜多层结构的低温调控。利用拉曼散射光谱(Raman)、紫外可见透射光谱以及稳/瞬态光致发光(PL)谱等检测手段对薄膜的微观结构、能带特征以及发光特性进行了分析。光吸收谱分析表明,nc-Si粒子尺寸及其a-SiOx边界层共同影响薄膜的光学带隙。稳/瞬态PL谱分析表明,多层结构发光表现为一个固定于1.19eV附近的发光峰和一个随nc-SiOx层厚度增加而发生红移的发光峰,其中固定发光峰归因于非晶SiOx网络中缺陷发光,发光衰减寿命约在4.6μs,峰位可调的发光峰为nc-Si量子限制效应-缺陷态复合发光,对应两个发光衰减过程,其中慢发光衰减寿命随nc-SiOx层厚度增加由9.9μs增加到16.5μs,快发光衰减过程基本保持不变。低温PL谱的温度依赖特性进一步表明,薄膜样品的发光主要表现为nc-Si的量子限制效应发光。Nc-SiO x/a-SiO x multilayer films were deposited using very-high-frequency plasma enhanced chemical vapor deposition(VHF-PECVD),to investigate the application of silicon quantum dots in solar cells.Transmission electron microscopy(TEM)images revealed that a multilayer structure was achieved by adjusting the thickness of the nc-SiO x layer at low temperature.Based on Raman scattering,UV-visible transmission,and steady/transient photoluminescence(PL)spectra,the microstructure,energy band,and photoluminescence properties of the films were characterized,respectively.Absorption spectra analysis indicated that the combination of the nc-Si and a-SiO x matrices affected the optical band gap of the films.The PL spectra of the multilayer films exhibited two distinct peaks as the thickness of the nc-SiO x layer was increased:a peak fixed at 1.19 eV,and another red-shifted peak near 1.45 eV.The fixed PL peak originated from radiative defects in the a-SiO x matrix,which corresponds to a PL decay life of approximately 4.6μs.The red-shifted PL peak was attributed to a complex quantum confinement effect-defect state luminescence mechanism.This is related to two PL decay processes including a slow PL decay life,which increased from 9.9 to 16.5μs,and a fast decay life,which was constant.The temperature-dependent PL properties further signified that the origin of the PL of the multilayer films was mainly attributed to quantum confinement effects in nc-Si.

关 键 词：纳米硅氧多层薄膜 微观结构 能带特征 光致发光 量子限制效应 

分 类 号：O484.41[理学—固体物理]